Femtosecond Photophysical and Photochemical Dynamics of DNA Building Blocks

The DNA bases adenine (A), cytosine (C), guanine (G), and thymine (T) stand out for their extraordinary photochemical stabilities which arise owing to ultrafast electronic deactivation processes. After absorption of a UV photon, the molecules are thereby returned to their ground electronic states before chemical reactions in the excited states can cause profound damage. We are studying the underlying ultrafast dynamics of the different building blocks of DNA by femtosecond fluorescence and absorption spectroscopies.